I actually had a conversation with one of the "ladies" from one of the "last time we'll call you" calls. She was rude and hung up before I could tell her to take me off their list because I'm on the do not call.
Report them to the do not call list (www.donotcall.gov). If they get enough complaints they start an investigation, hopefully find out who they are and shut them down. I got a very similar call a few weeks ago with a California area code, but I suspect it may be the same operation.